Process utilizing fluidized beds in the dyeing of fabrics, yarns and the like



United States Patent PROCESS UTILIZING FLUIDIZED BEDS IN THE DYEING OF FABRICS, YARNS AND THE LIKE Francis George Audas, Cheadle Hulme, England, assignor to The British Rayon Research Association, Manchester, England, a British association No Drawing. Application May 3, 1956 Serial No. 582,335

Claims priority, application Great Britain May 7, 1955 7 Claims. (Cl. 8--151) This invention concerns the dyeing of filaments, fibres, threads, yarns, films and sheets of Terylene (R.T.M.), nylon, cellulose triacetate rayon or secondary acetate rayon or the like synthetic materials or of fabrics made therefrom.

Considerable difiiculty has hitherto been experienced in the dyeing of Terylene and nylon and, to a lesser extent, of cellulose triacetate rayon and secondary acetate rayon or the like synthetic materials and in the fixing in reasonable times at atmospheric temperatures of a satisfactory amount of dye with the requisite uniformity and without damage to the dyed material. For example the time required for dyeing Terylene fabric or yarn with a given disperse-acetate dye, which at moderate temperatures of the order of 85 C. is excessive may be considerably reduced at temperatures of the order of 120 C. but such processing normally requires the dyeing unit to be pressurized, and this in inconvenient and adds to the expense of the process.

Considerable effort has been directed to the developrnent of high temperature dyeing techniques which do not involve pressurization of the dyeing unit. It has been found possible for example to pass certain fabrics through a suspension of dyestuff in an aqueous bath, to dry the fabric, and then heat it to a temperature high enough to permit the padded and unfixed dye to diffuse into the fibres of the fabric material. In such methods, in order to achieve satisfactory dyeing, it is frequently necessary to use temperatures of 200 C. or more, for periods of from ten to thirty seconds. These high temperatures are disadvantageous as they tend to cause considerable shrinkage of the material. This difficulty may be overcome by prior heat setting, in conjunction with stentering at a higher temperature still but the temperatures involved might Well reach a level at which the material is damaged. For example, the melting point of T erylene is only about 240 C. Stentering during the dyeing process is also likely to give rise to local temperature variations and consequent uneven dyeing.

Other attempts at overcoming these difficulties have included the addition to the dyeing bath of carriers or swelling agents but the known agents, while enabling the dyeing and fixing times and temperatures to be decreased,

' have suffered from the disadvantage of imparting a disagreeable odour to the material under treatment, or of impairing the light fastness of the dye, or of failing to provide the requisite uniformity of colour.

The main object of the invention is to provide an improved method of dyeing filaments, fibers, threads, yarns, films and sheets of Terylene, nylon, cellulose triacetate rayon and secondary acetate rayon and of fabrics made therefrom and We have found that this object may be achieved by the use in conjunction with certain dyeing assistants in the dyebath of the step of drying and heat treatment or of heat treatment described and claimed 2,901,312 Patented Aug. 25, 1959 "ice in the complete specification of our co-pending application Nos. 547,681, filed November 18, 1955, and 507,705, filed March 11, 1955, and now Patent No. 2,785,478. In some cases the object may also be achieved, though to a lesser extent, if the said dyeing assistants are used with other methods of drying and heating already known in connection with the said material under treatment. These assistants are glycerine, triethanolamine, diacetin, erythritol, penta erythritol, ethylene glycol, di-ethylene glycol, di-ethylene glycol diaeetate, D-glucose monohydrate, thiourea, urea, ammonium thiocyanate, hexamine, a mixture of urea and ethylene glycol, a mixture of thiourea and ethylene glycol, a mixture of penta erthritol. and thiourea, a mixture of glycerine and thiourea, and a mixture of diethylene glycol diacetate and thiourea (hereinafter and in the claiming clauses hereof called a defined dyeing assistant) According to the present invention a method of dyeing filaments, fibers, threads, yarns, films and sheets of Terylene, nylon, cellulose tri-acetate rayon or secondary acetate rayon or the like synthetic materials or of fabrics made therefrom comprises passing the material under treatment into a dyebath containing a defined dyeing assistant and a dye, padding the dye on to the material under treatment and then passing the material under treatment through a bed of hot discrete particles, While the bed is subjected to an upward gaseous current, the size and weight of the particles, the velocity and nature of the current and the disposition of the material under treatment being so chosen that the forces exerted by the current on the particles are suificient to counter-balance the gravitational force on free particles and to expand the bed, thus allowing movement of the particles, but is insufficient to convert the bed into a uni-directional stream of moving particles, and the temperature in the bed being so chosen that the dye is fixed in the ma terial under treatment.

The nature of the said bed (hereinafter and in the claiming clauses hereof called a fluidised. bed) and the manner of making the same is fully described in the specifications of the said co-pending applications.

The actual proportion of the defined dyeing assistant in the bath may vary within fairly wide limits and the best proportion can easily be determined for any particular material by simple trial. It may be as low as 1% or as high as 20% but it will preferably be between 5% and 12% according to the assistant used, the percentages being by volume, or weight as the case may be, depending on whether the assistant is a liquid or a solid.

We have found that the present invention enables dyeing to be more readily effected than with known methods and with advantages not possessed by the known methods.

The invention will now be illustrated by the following examples.

Example 1 Four dyebath liquors were prepared each of which contained 5% by weight of the dye Duranol Brilliant Violet BR300 (C.I. 62,030) and 0.2% by weight of the wetting agent Perminal PP. One liquor contained no assistant, one contained 5% by volume of glycerine, one contained 5% by volume of diacetin, and one contained 5% by volume of triethanolamine.

Nylon and Terylene continuous filament fabrics were padded through the dyebath liquors, and, after mangling, were passed through a fluidised bed of sand at C., the time in the bed being ten seconds. The dyed fabrics were treated with a hot soap solution to detach unfixed Ci) dye and after rinsing and drying were analysed for dye content. The results were as follows:

Percent by Percent by Percent by volume of dye bath assistant Weight of weight of dye on dye on nylon Terylene None 1. 48 0. 93 5% glycerine 1.82 1. s4 5% diace'tin 1. 99 1. 39 5% triethanolarnlne..- 1. 80 1. 15

Example 2 The same procedure as-in Example 1 was followed except that the dyebath liquor contained 5% by weight of the dye Seris'ol Fast Red 3BL ('CJI. 61,140) and the fabrics usedwere of continuous filament secondary acetate rayon, cellulose triacetate rayon, and Terylene.

The results were as follows:

The same procedure as in the preceding examples was followed except that 10% :by weight of Duranol Red X 3B 300 (0.1. 62,015) dye was used in the liquor, the

fabrics were of continuous filament Terylene and'spun Terylene respectively, and'ten liquors were used, the'assistants being set out in the results which were as follows:

Percent by Percent by Weight'oi v weight of Percent by volume or weight (as theease dye on dye on may 'be) of dye bath assistant continuous Spun filament Tyrelene 'Tyrclene None "1: S8 2320 5% g1ycerene .L 2. 49 v 2. 71 3.3% ethy ene glycol. 2.15 I 2. 29 7.6% hexamine 1:98 2. 40 -10.9% D-glucse monohydra 2. .44. 2. 42 4.1%ammonii1m thiocyanateu 1: 97 2. 72 4.1% .thiourea i .2. 28 2. 41 3.3%.11rea 2.103. 2. 51 1;65%'urea Kl.65% ethylene g'lycol '2: "2. 35 2.1% thiourea K 1.65% ethylene. glycol 2. 32 2.38 2.5% glycerine K 2.15% thiourea 2. .40 ,2, 83

It .is to be understood that ,passage through the hot fluidised bed dries .thefabric as wllas fixesthedye when the fabric is passed straight from thedyebath to .theibed as in the foregoing examples. Theaactual .fixing timeis therefore only part not .the total time .in the bed. iForexample if the total time is 10 seconds, drying may :take three 'or .four seconds, :and :fixing the remainder .of the time. Drying need not necessarily be carried out in .a fluidised bed and it is. possiblewwithout serious loss of advantage to dry the material by other methods and then heat treat :the material to fix the dye by passing .through a fluidised "bed. Likewise (the increased weights of .dye fixed .on the material under treatment result from the .use of the defined dyeing assistant and it is thus possible to obtain some of the advantagestof the inventionbythe use of the defined dyeing assistants with other .forms .of .drying and heat treatment. Glycerine .is preferred .asthe defined dyeing assistant as it is cheap and easily removed from'the dyed material. Other-ide'fined .dyeingassistants which are .also cheap and easilyremoved- .are .diacetin and D-g'lucose' monohydrate;

The process of the invention gives an inc e s i th weight of dye which is fixed on a fabric for a given time and temperature of heat treatment.

What I claim is:

1. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising the steps of passing a synthetic fibrous material adapted to be dyed into a dye bath containing a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through a bed of hot, solid, discrete particles, while subjecting the bed'to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is sufficient to counter-balance the gravitation- 81 force on free particles and to expand the bed thus allowing movement of the particles but is insuificient to convert the bed into a unidirectional stream of moving particles, the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough, being adjusted to fix said dye into said synthetic fibrous material.

2. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising the steps of passing a synthetic fibrous material adapted to be dyed and being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon into a dye bath containing a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through abed of hot, solid, discrete particles, While subjecting the bed to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is sufiicient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles but is insufficient to convert the bed into a undirectional stream of moving particles, the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough being adjusted to fix said dye into said syntheticfibrous material.

3. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising'the steps of passing a synthetic fibrous material adapted toibedyedand being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon into a dye bath containing a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through abed of hot, solid, discrete particles .of siliceou sand, while subjecting the bed to an upward gaseouscurrent, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is sufficient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles butisinsufiicient to convert the bed into a -,unidirectional-stream of moving particles, the temperature vof thebedbeingsubstantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is z-passcd therethrough .being adjusted to ,fiX said dye .into saidsynthetic 'fibrous material.

4. 'A method of dyeing filaments, fibres, ithreads, yarns, films, and sheets made of a synthetic fibrous material, comprising .the steps .of passing a synthetic fibrous material .adapted tobedyed and being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon into a dye bath containing a dyeing assistant, the dye of said dye bath being a disperse-acetate dye adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through a bed of hot, solid discrete particles, while subjecting the bed to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is suificient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles but is insufiicient to convert the bed into a unidirectional stream of moving particles, the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough being adjusted to fix said dye into said synthetic fibrous material.

5. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising the steps of passing a synthetic fibrous material adapted to be dyed and being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon, into a dye bath containing glycerine as a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through a bed of hot, solid, discrete particles, while subjecting the bed to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is sufficient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles but is insufficient to convert the bed into a unidirectional stream of moving particles, the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough being adjusted to fix said dye into said synthetic fibrous material.

6. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising the steps of passing a synthetic fibrous material adapted to be dyed and being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon into a dye bath containing diacetin as a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through a bed of hot, solid, discrete particles, while subjecting the bed to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current being so chosen that the force exerted by the current is sufiicient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles but is insuificient to convert the bed into a unidirectional stream of moving particles, the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough being adjusted to fix said dye into said synthetic fibrous material.

7. A method of dyeing filaments, fibres, threads, yarns, films, and sheets made of a synthetic fibrous material, comprising the steps of passing a synthetic fibrous material adapted to be dyed and being selected from a group consisting of Terylene, nylon, cellulose triacetate, rayon and secondary acetate rayon into a dye bath containing D-glucose monohydrate as a dyeing assistant, the dye of said dye bath being adapted to be fixed at a predetermined temperature; padding said dye onto said synthetic fibrous material; and passing the thus treated synthetic fibrous material containing said dye through a bed of hot, solid, discrete particles, while subjecting the bed to an upward gaseous current, the size and weight of the particles and the velocity and nature of the current is sufficient to counter-balance the gravitational force on free particles and to expand the bed thus allowing movement of the particles but is insufiicient to convert the bed into a unidirectional stream of moving particles,the temperature of the bed being substantially at said predetermined temperature and the rate at which said treated synthetic fibrous material is passed therethrough being adjusted to fix said dye into said synthetic fibrous material.

References Cited in the file of this patent UNITED STATES PATENTS 2,080,254 Dreyfus May 11, 1937 2,349,282 Kern May 23, 1944 2,785,478 Audas Mar. 19, 1957 OTHER REFERENCES Giradet: Industrie-Anzeiger, vol. 75, No. 12, February 10, 1953, pp. 141-143.

Saville, A.K.: The Printing of Nylon Piece Goods, Am. Dyestuff Reporter, September 19, 1949, pp. 673-674.

Du Pont: The Techn. Bull., vol. 5, No. 2, June 1949, pp. 83-102.

Kite, RP. and Roberts, E.I.: Fluidization in Non- Catalytic Operations, Chem. Eng, December 1947, pp. 112-115.

Diserens, L.: Les Produits Aux. dans Uni-Textile, Rev. Gen. Mat. Col., March 1957, pp. 89-100.

Am. Dyestuff Rep. (1), August 17, 1953, pp. 543, 544.

Am. Dyestufi Rep. (11), February 18, 1952, p. 104. 

1. A METHOD OF DYEING FILAMENTS, FIBRES, THREADS, YARNS, FILMS, AND SHEETS MADE OF A SYNTHETIC FIBROUS MATERIAL, COMPRISING THE STEPS OF PASSING A SYNTHETIC FIBROUS MATE RIAL ADAPTED TO BE DYED INTO A DYE BATH BEING ADAPTED TO ING ASSISTANT, THE DYE OF SAID BATH BEING ADAPTED TO BE FIXED AT A PREDETERMINED TEMPERATURE; PADDING SAID DYE ONTO SAID SYNTHETIC FIBROUS MATERIAL; AND PASSING THE THUS TREATED SYNTHETIC FIBROUS MATERIAL CONTAINING SAID DYE THROUGH A BED OF HOT, SOLID, DISCRETE PARTICLES, WHILE SUBJECTING THE BED TO AN UPWARD GASEOUS CURRENT, THE SIZE AND WEIGHT OF THE PARTICLES AND THE VELOCITY AND NATURE OF THE CURRENT BEING SO CHOSEN THAT THE FORCE EXERTED BY THE CURRENT IS SUFFICIENT TO COUNTER-BALANCE THE GRAVITATIONAL FORCE ON FREE PARTICLES AND TO EXPAND THE BED THUS ALLOWING MOVEMENT OF THE PARTICLES BUT IS INSUFFICIENT TO CONVERT THE BED INTO UNIDIRECTIONAL STREAM OF MOVING PARTICLES, THE TEMPERATURE OF THE BED BEING SUBSTANTIALLY AT SIAD PREDETERMINED TEMPERATURE AND THE RATE AT WHICH SAID TREATED SYNTHETIC FIBROUS MATERIAL IS PASSED THERETHROUGH, BEING ADJUSTED TO FIX SAID DYE INTO SAID SYNTHETIC FIBROUS MATERIAL. 